Grad students

Jess Vickruck, PhD student

I am primarily interested in potential mechanisms underlying social group formation and maintenance. Currently, I am investigating these questions using the facultatively social carpenter bee (Xylocopa virginica). Female carpenter bees can nest alone or in groups, but initial observations indicate that social nests display a bizarre division of labour where by the dominant female does all of the foraging and all of the egg laying, while some females do nothing (tertiaries) and others do some foraging or try to relocate to other nests in the aggregation (secondaries). Nests are occupied for many years, with females reusing tunnels as well as expanding nest architecture over time. The focus of my PhD research is to understand the behavioural and genetic relationships among carpenter bees at different scales. This includes how reproductive strategies are determined within nests, the costs and benefits of each strategy, and the genetic relationships among of individuals in a nest, aggregation or across their distribution. By assessing behavioural factors influencing reproductive strategies in X. virginica, I hope to identify which characteristics lead to each reproductive strategy, as well as why multiple reproductive phenotypes are maintained in the population. By quantifying both fine and course scale population structure, I aim to provide valuable insights into how dispersal and relatedness shape group formation in this species.

David Awde, PhD student

My PhD work in the Brock Bee Lab is focused on the reproductive ground plan hypothesis (RGPH) as a means to explain the evolution of eusociality. Queens and workers in eusocial species, such as the honey bee, are believed to have evolved from a proposed solitary ancestral reproductive life cycle. The reproductive phase of this cycle is now expressed in queens and the non-reproductive phase in workers. The RGPH hypothesis has been extensively studied in different worker reproductive phenotypes of the highly eusocial honey bee and very few studies have examined gene expression between queens and workers. I plan to make this queen and worker comparison in a primitively eusocial sweat bee – Lasioglossum laevissimum. Using honey bee genes identified as having differential expression for reproductive and foraging phenotypes I will identify gene homologs present in L. laevissimum and compare their expression in queens and workers for different time points through their colony cycle.